This invention relates to epoxy resin compositions and solid state devices encapsulated therewith. The invention also relates to a method for encapsulating a solid state device.
Solid state devices, sometimes referred to as semiconductor devices or opto-electronic devices, comprise light emitting diodes (LEDs), charge coupled devices (CCDs), large scale integrations (LSIs), photodiodes, vertical cavity surface emitting lasers (VCSELs), phototransistors, photocouplers, opto-electronic couplers and the like. Such devices often exhibit special packaging needs. High-efficiency, high lumen, solid-state white LEDs require a novel packaging material which can withstand more demanding conditions than those required by typical low-intensity, longer wavelength LEDs. Common packaging materials will often undergo a gradual loss of optical and mechanical properties due to the combination of thermal, oxidative and photodegradation processes.
There is thus a continuing need for novel packaging material for solid state devices, such packaging material desirably possessing properties such as high transmission in a range from near UV to the visible wavelength, long-term thermal stability, oxidative stability, UV stability, thermal compliance, moisture resistance, transparency, crack resistance, polishability characteristics, compatibility with other materials used to envelope the solid state device with low color, and high reflective index.
The present inventors have discovered curable resin compositions ideally suited for an encapsulation of solid state devices such as light emitting diodes. In one embodiment, the present invention relates to a curable epoxy resin composition for encapsulation of a solid state device, which comprises (A) at least one silicone resin, (B) at least one epoxy resin, (C) at least one anhydride curing agent, (D) at least one siloxane surfactant, and (E) it least one ancillary curing catalyst.
In another embodiment of the present invention, there is provided a packaged solid state device comprising: (a) a package; (b) a chip; and (c) an encapsulant comprising: (A) at least one silicone resin, (B) at least one epoxy resin, (C) at least one anhydride curing agent, (D) at least one siloxane surfactant, and (E) at least one ancillary curing catalyst.
In another embodiment of the present invention, there is provided a method of encapsulating a solid state device comprising placing the solid state device into an encapsulating composition comprising (A) at least one silicone resin, (B) at least one epoxy resin, (C) at least one anhydride curing agent, (D) at least one siloxane surfactant, and (E) at least one ancillary curing catalyst.
Various other features, aspects, and advantages of the present invention will become more apparent with reference to the following description and appended claims.